Spiritmaster's Blade

Weapon Finesse, Light, Range, Thrown, Spiritmaster Varies

Once per day, when you hit a melee attack with this dagger, you can activate it. The creature must succeed on a DC 14 constitution saving throw. On a failed save it takes an additional 1d8 necrotic damage and the dagger gains a charge of magical energy. This charge can be consumed to recieve a spell slot of 3rd level or lower. Further activation while the dagger holds a charge is impossible.
If the creature is a construct, it automatically fails the saving throw and is instead knocked unconscious for a number of days equal to the necrotic damage rolled

For every attuned Spiritmaster item equipped that is charged, the Blade does an extra 1d6 necrotic damage on every attack.